Aspirating syringe



Dec. 21, 1965 N. w. MELOTT ASPIRATING SYRINGE Filed March 1, 1956INVENTOR FIG. 3

ATTORNEY United States Patent m 3,224,445 ASPIRATING SYRINGE Norman W.Melott, Monndsville, W. Va., assignor to Cook-Waite Laboratories, Inc.,New York, N.Y., a corporation of Delaware Filed Mar. 1, 1956, Ser. No.568,873 3 Claims. (Cl. 128-218) This invention relates to a new andimproved plunger rod for use in a syringe with a disposable cartridgehaving a piston cork, and the principal object of the present inventioncomprises the provision of a dental-type cartridge syringe having amovable plunger rod provided with a retractible barbed or spearpointhead at the inner end thereof for piercing the piston cork of theconventional disposable cartridge and thereby alfixing the plunger rodof the syringe to the cartridge piston cork, converting the conventionaldisposable cartridge into an aspirating cartridge.

In a conventional dental cartridge syringe, the plunger rod merely bearsupon the piston cork of the cartridge and presses the cork inwardly toexpel the cartridge contents through the syringe needle, but this doesnot provide for an aspirating action, which may be accomplished by aslight retraction of the cartridge piston cork in order to provide theoperator with an indication as to whether or not the needle of thesyringe has punctured a vein.

This invention provides simple, economical, and easily operated meansfor quickly affixing the plunger rod of the syringe to the piston corkof the cartridge, so that both aspiration and injection may be provided,merely by thrusting the novel barbed plunger rod inwardly, therebypiercing the piston cork with a sharp arrow or spearpoint, and henceassuring fixation of the plunger rod with respect to the cartridgepiston cork; such fixation, however, being easily disrupted when thecartridge has been used and it is desired to throw it away merely bymanually retracting the extending spearpoint within a sleeve providedfor the purpose, and thus in effect pushing the cartridge piston corkfrom the spearpoint.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which FIG. 1 isa view in elevation of a syringe according to the present invention,parts being broken away and in section;

FIG. 2 is an enlarged section in the line 22 of FIG. 1;

FIG. 3 is an enlarged section on line 33 of FIG. 1;

FIGS. 4 and 5 are sections on the respective lines in FIG. 2; and

FIG. 6 is a view similar to FIG. 2 but illustrating the action of thespearpoint.

The invention may be used with any type of syringe presently used withdisposable cartridges. The syringe illustrated is provided with aconventional barrel 10 having an observation window or windows 12therein for viewing the cartridge for information as to content andaspiration. The barrel is provided with the usual needle 14 whichextends rearwardly interiorly of the barrel to puncture the forward end16 of the disposable ampoule or cartridge indicated at 18.

The syringe is provided with an axially movable plunger rod generallyindicated at 20 which is used to engage the cartridge piston cork 22 tomove the same along the cartridge for expelling the contents thereofthrough the needle 14.

The syringe also has a locking sleeve 24 which is threaded into the head26, the latter being hinged as at 28 Patented Dec. 21, 1965 ice to thesides of the barrel. The head is provided with a fingerhold 30. When thelocking sleeve is retracted, it becomes disengaged from the inner end ofthe barrel and thus the head 26 may be pivoted in order to expose theinner end of the barrel. However, when the locking sleeve is tightenedwith the head in place, the head becomes relatively immovable for use ofthe syringe in the normal manner.

The plunger rod for any syringe comprises a pair of relatively axiallymovable parts, one of which is shown as a rod indicated at 32 and theother part being a surrounding elongated sleeve 34 which is providedwith an annular lateral flange 36 at the inner end thereof for forming afirm contact with the cartridge plunger 22, see particularly FIG. 2.

The inner end of the rod 32 of the present case is provided with asharpened spearpoint indicated at 38. This spearpoint may be madeintegral with the rod 32, or it may be made separable and replaceable asfor instance by means of screw-threads such as are shown at 40. Thespearpoint is provided with barbs 42 and these may be sharpened at theirrear surfaces 44 (see FIG. 6) for a purpose to be described.

The rod 32 has a limited axial motion relative to the surrounding sleeve34 and limiting means may be provided as for instance by a throughcrosspin 46 in the rod 32 which engages a shoulder 48 to limit theextent of outward motion of the spearpoint relative to the inner end ofthe sleeve 34; and it may engage a necked-down or brazed collar 50forming the limit stop for the other end of relative motion of rod 32 inthe sleeve 34. In any event, the spearpoint 38 is provided withapproximately the limit of motion between the solid and dotted lineshowings thereof in FIG. 6. This spearpoint may be completely housedwithin the sleeve or it may be extended outwardly thereof, so that thebarbs 42 are in spaced relation with the inner end surface 52 of theflange or annular abutment 36.

The outer end of rod 32 is provided with an enlargement as at 54, thisenlargement providing a guide and abutment for a coil spring 56 whichnormally serves to maintain the spearpoint in retracted housed positionwhen not in use.

In the use of the device, the locking sleeve 24 is backed off, the head26 pivoted to one side, the disposable cartridge is inserted in thebarrel; the head is then re-positioned, the locking sleeve is tightenedand the rod 20 is moved forwardly so as to engage the flange 36 thereofwith the exterior surface of the cartridge piston cork 22. Continuedthrust on the plunger rod 20 results in the piercing of "the cork 22 bythe spearpoint 30 until it becomes completely embedded therein as inFIG. 2. After the plunger is fixed, the needle is attached to thesyringe.

The plunger rod of the syringe and the cork of the cartridge are nowfixed together and the syringe may be operated both for aspirating andinjecting as will be clear to those skilled in the art.

When the cartridge is to be disposed of, the rod 32 is retracted byfingerpiece 58, and this action brings the spearpoint back insleeve-housed position as shown in solid lines in FIG. 6, thusdisrupting the sprearpoint from the cork 22, allowing the entirecartridge to be disposed of, and a new cartridge replaced in the barrel.The spearpoint is more easily withdrawn from the cork due to the sharpedges 44 on the barbs.

It will be seen as in FIG. 2 that when the spearpoint is in itsforwardmost position, the flange 36 engages the exposed surface of thepiston cork 22. The spring 56, tending to retract the spearpointmaintains this relationship, so that upon aspiration and injection, =butparticularly upon the latter operation, the sleeve 34 and rod 32 act asa unit and the sprearpoint alone is not depended upon to provide themotion of the cartridge piston cork 22.

Having thus described my invention and the advantages thereof, I do notwish to 'be limited to the details herein disclosed, otherwise than asset forth in the claims, but what I claim is:

1. An aspirating syringe comprising a generally cylindrical magazine, aplunger reciprocable longitudinally within said magazine, and asubstantially flat a'spirator hook rigidly fixed to the forward end ofsaid plunger; said magazine being adapted to receive therein acylindrical ampoule having a piston stopper slidable forwardly thereinto expel a medicament therefrom and retractible to afford aspiration,said hook having substantially similar opposite side faces approximatelyparallel to the line of reciprocal movement of the plunger; said hookbeing adapted to become embedded in said stopper without turningrelatively thereto, and having a portion opposing its withdrawal fromsaid stopper upon a retraction stroke of the plunger.

2. An aspirating syringe according to claim 1, said hook having a neckportion, and said withdrawal-opposing porportion of the hook being abarb extending laterally from said neck portion.

3. An aspirating syringe according to claim 2, said barb having arearwardly pointing end.

4 References Cited by the Examiner UNITED STATES PATENTS RICHARD A.GAUDET, Primary Examiner.

JOHN R. KLINE, HAROLD B. WHITMORE, ROBERT E. MORGAN, RICHARD J. HOFFMAN,Examiners.

J. M. CRAWFORD, D. GREER, ADELE M. EAGER,

RENE D. TEGTMEYER, Assistant Examiners.

1. AN ASPIRATING SYRINGE COMPRISING A GENERALLY CYLINDRICAL MAGAZINE, APLUNGER RECIPROCABLE LONGITUDINALLY WITHIN SAID MAGAZINE, AND ASUBSTANTIALLY FLAT ASPIRATOR HOOK RIGIDLY FIXED TO THE FORWARD END OFSAID PLUNGER; SAID MAGAZINE BEING ADAPTED TO RECEIVE THEREIN ACYLINDRICAL AMPOULE HAVING A PISTON STOPPER SLIDABLE FORWARDLY THEREINTO EXPEL A MEDICAMENT THEREFROM AND RETRACTIBLE TO AFFORD ASPIRATION,SAID HOOK HAVING SUBSTANTIALLY SIMILAR OPPOSITE SIDE FACES APPROXIMATELYPARALLEL TO THE LINE OF RECIPROCAL MOVEMENT OF THE PLUNGER; SAID HOOKBEING ADAPTED TO BECOME EMBEDDED IN SAID STOPPER WITHOUT TURNINGRELATIVELY THERETO, AND HAVING A PORTION OPPOSING ITS WITHDRAWAL FROMSAID STOPPER UPON A RETRACTION STROKE OF THE PLUNGER.